package com.liuyuan.chinaoracle.utils;

import org.springframework.http.HttpHeaders;
import org.springframework.http.server.ServerHttpRequest;

import java.net.InetAddress;

/**
 * 网络工具类.
 */
public final class NetUtils {

    private NetUtils() {
    }

    /**
     * 获取客户端 IP 地址.
     *
     * @param request 网络请求
     * @return 响应字符串
     */
    public static String getIpAddress(ServerHttpRequest request) {
        HttpHeaders headers = request.getHeaders();

        String ip = headers.getFirst("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = headers.getFirst("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = headers.getFirst("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddress().getAddress().getHostAddress();
            if (ip.equals("127.0.0.1")) {
                // 根据网卡取本机配置的 IP
                InetAddress inet = null;
                try {
                    inet = InetAddress.getLocalHost();
                } catch (Exception e) {
                    e.printStackTrace();
                }
                if (inet != null) {
                    ip = inet.getHostAddress();
                }
            }
        }
        // 多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
        if (ip != null && ip.length() > 15) {
            if (ip.indexOf(",") > 0) {
                ip = ip.substring(0, ip.indexOf(","));
            }
        }
        if (ip == null) {
            return "127.0.0.1";
        }
        return ip;
    }

}
